JPS5952692A - heat sensitive recording material - Google Patents

Abstract

PURPOSE:To improve the density and the sharpness of an image, in a heat sensitive recording material obtained by forming a heat sensitive color forming layer on a support, by laminating a high molecular substance layer with heat conductivity of a predetermined value or less onto the heat sensitive color forming layer. CONSTITUTION:For example, a heat sensitive color forming layer containing a leuco dye, a color developer and a binder is formed on a support such as paper or a plastic film and colorless or light colored high molecular substance with heat conductivity of 0.15kcal/m.Hr. deg.C or less such as polystyrene, polybutadiene or polyester is used to be laminated to said color forming layer in a thickness of 0.5-10mum, pref., 1.0-3mum. Thus obtained heat sensitive recording material can sufficiently perform the blocking of heat transmitted to the heat sensitive layer, especially, in performing recording by a close adhesion reflection printing system.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an improvement of the present invention.

When thermal paper is brought into close contact with the original, the original is heated with an infrared lamp, etc., and an image is formed on the thermal paper using the heat.
In order to obtain a normal colored image, for example, a thermal paper is placed on the top surface of a contact glass so that the surface of the thermosensitive coloring layer is in contact with the glass surface, and the surface of the thermal paper that does not have the thermosensitive coloring layer is placed on top of the contact glass.
The original is stacked on top of the second one, and an infrared lamp is irradiated from the bottom surface of the contact glass. When heating an original in this way, the black image area of the original absorbs the heat rays, becoming significantly higher in temperature than the non-image area, and this high heat is transferred from the back of the thermal paper to its thermosensitive coloring layer. A normal colored image is formed in the heat-sensitive coloring section.

However, in such a recording method (copying method) using the contact reflection printing method, there is a problem that the heat transferred to the thermosensitive color forming layer is further transferred to the contact glass and is not used efficiently.

The present inventors have completed the present invention as a result of repeated research in order to solve such problems.

That is, according to the present invention, a thermosensitive coloring layer is formed on a support, and a layer having a thermal conductivity of 0 or 15 kcal/n+·l is formed on the thermosensitive coloring layer.
Provided is a heat-sensitive recording material characterized by comprising a seed layer of a polymer material having a temperature of -1r.°C or less.

In the present invention, the polymer material layer formed on the heat-sensitive coloring layer has a thermal conductivity of 0, 15 kcat/n+・Il.
It is formed using a polymer material with r'c or less. Examples of such polymeric substances include polystyrene, polybutadiene/polyester, polypropylene, polymethyl methacrylate, styrene-butadiene resin, phenol resin, methyl methacrylate-styrene copolymer, olefin-vinyl alcohol copolymer; 1
4' Sourethane, polyvinyl chloride, ethyl cellulose,
Cellulose acetate I-, acetal p-7-IJ-7-
A colorless or slightly colored material such as 1β-dextrin is used. In particular, it is preferable to use a material having a lower thermal conductivity than the support.

In the present invention, the polymer material layer is preferably 0.5 to 10 .mu.m, preferably 1.mu. o~3.0μm
It is formed with a layer thickness of 11.

In the present invention, as described above, a polymer substance having a thermal conductivity of 0.15 kcat/+n·llr'C or less is used;
If it is larger than al/m44r.''C, it will not be possible to sufficiently block the heat transferred from the image area of the document heated to a high temperature to the thermosensitive coloring layer through the support of the thermosensitive recording material.

In the present invention, the heat-sensitive color forming layer provided on the support 2 can be one containing a conventionally used leuco dye and color developer.

As the leuco dye, colorless or slightly light-colored triphenylmethane-based, fluoran-based, phenothianone-based, auramine-based, and spirobiol-based 1'' leuco dyes are preferred, such as crystal violet lactone, malachite green lactone, 3,3 -bis(p-dimethylaminophenyl)-6-aminophthalide, 3.3-bis(p-dimethylaminophenyl)-6p) luenesulfonamide Y, 3-diethylamine-6-methyl-7-N-phenylaminofluorane , 3-diethylamine-7-dibenonoraminofluorane, 3-dibutylamino-6-methyl-7-chlorofluorane, a-/'ethylamino-6-methyl-7-chlorofluorane, 3- Diethylamine-7-phenylfluoran, 3-methylamino-6-Medquin fluoran, 3-dimethylamine-7-
(N-methyl-p-)luidino)fluoran, 6'-chloro-8'-methquinebenzoindolinopyrillospiran, 3-morpholino-5,6-,)penzofluoran/,
3-Methyl-no-β-naphthospiropyran, Knzo-β
-Naphthospiropyran, etc.

As the color developer for the leuco dye, various electron-accepting substances that develop color by reacting with the leuco dye under heat are used, such as phenolic acid substances, organic acids, esters of organic carzene acids, or polyvalent metals. There are 几Y''WAC, specifically those shown in 1 and -1.

α-nasol, β-naphthol, 4-+-butylphenol, 4-phenylphenol, 2,2-his(+
)-Hydroxyphenyl)solonξone, 2゜2'-his(p-hydroquinphenyl)butane, 4゜4'-7 chlorohequinritenophenol, 4.4'-1nobroe'
) 7':/bis(2-1-bu-1-lphenol)
, benzoic acid, salicylic acid, zinc 3,5-butylsalicylate, tin 3,5-not-butylsalicylate, propyl hydroquinobenzoate, pen/nor hydroquinobenzoate, and the like.

Examples of the binder include conventional binders, such as gelatin, tensin, h-10x7-ethyl cellulose, polyacrylamide, polyacrylic acid, calxyethyl cellulose, metquin cellulose, polyvinyl alcohol, and polyvinylpyrrolidone. Other auxiliary additives include, for example, clay, kaolin, calcium carbonate, titanium oxide, silica, polystyrene fine particles, urea-Polmason resin fine particles, etc. I,
Subtle particles: Heat-soluble substances with a melting point of 50 to 150°C, such as higher fatty acid ami-t7 and its derivatives, higher fatty acid metal salts, animal and vegetable waxes, polyethylene, paraffin, petroleum waxes such as microcrystalline; surfactants, etc. be done.

The thermosensitive coloring layer component in the present invention is preferably a leuco type as described above, but it is clear that the present invention can also be applied to materials other than the leuco type, and conventional heat-sensitive copying paper or recording paper can be used. Those described in the related literature, such as those shown below, can be used as components of the thermosensitive coloring layer.

(a) A melting point of 100 to 100, which has a secondary alcoholic hydroxyl group and is described in Japanese Patent Publication No. 41-14510.
A composition of a combination consisting of a 180°C compound, sulfur and metal inorganic salts or metal acetates.

Here, examples of compounds having a primary quaternary alcoholic hydroxyl group include benzoin, 2-methquine benzoin, 4-
1lupennoin, 4-trimethylaminobenzine, 2-
Chlor-4'-trimethylamino is a benzoin compound such as Nzoino, tokicarbinols such as nophenylcarbinol, resorcinol, pyrogallol, 3-71 hydroquine toluene-4-sulfonic acid, 4-nitroresonone, 4,6-nobromresol/ Examples include phenolic compounds such as No. 7, fatty acid polyhydric alcohols such as erythritol, sorbitol, galactose, maltose, mannitol, and saccharose. Metal inorganic salts and metal acetates include many metals that react with hydrogen sulfide to produce colored sulfides, such as copper, lead, tin, molybdenum, cobalt, lithium, nickel, Manganese, titanium, antimony, a) rum, osmium, mercury, iron, S lium, bismuth, arsenic, magnesium, indium, iridium, etc.

(1)) A composition consisting of a thermochromic compound described in Japanese Patent Publication No. 41-14511, in which various inorganic metal salts in the composition a are replaced with hexamethylenetetramine/metal salt adducts. thing.

(c) A composition comprising a combination of a carbohydrate and a dehydrating agent, as described in Japanese Patent Publication No. 42-13237.

Here, carbohydrates include saccharose, fructose,
Examples include galactose, starch, etc. - Strong water agents include sulfuric acid, acetic anhydride, anhydrous zinc chloride, and nomiladruenesulfonic acid.

In addition to the above-mentioned compositions, a number of combinations of compounds such as those described below are known as compositions made of compounds that develop color upon heating.

(b) Long-chain fatty acid iron salts such as ferric stearate and ferric myristate, tannic acid, gallic acid, -IJ-
Combination with phenols such as IJ ammonium thylate.

(b) Metal salts such as nickel, cobalt, lead, copper, iron, mercury, and silver salts such as acetic acid, stearic acid, and palmitic acid, and alkalis such as sulfide, strontium, strontium sulfide, and ζlium sulfide. Combination with earth metal sulfide-1 or a combination of the above organic acid heavy metal salt and an organic chelating agent such as S-nophenylcarbanide or nophenylcarbanide.

(c) Combinations of heavy metal oxalates such as silver, lead, mercury, and thorium oxalates and sulfur compounds such as I'bl-tetrathionate, sodium thiosulfate, and thiourea.

) with fatty acid ferric salts such as ferric stearate:
(Combination with aromatic polyhydroxy/compounds such as , 4-nobi-1''-roki/tetrasol-1-rumethane.

(e) A combination of an organic acid 11 metal salt such as iron oxalate or mercury oxalate and an organic polyhydroquino compound such as polyhydroquinone alcohol, glycol or glycol.

(f) A combination of a noble metal salt of an organic acid such as silver behenate or silver stearate and an aromatic organic reducing agent such as protocatechuic acid, spiroindane, or hydroquinone.

(G)-! ! Silk combination of fatty acid ferric salts such as ferric largolate and ferric laurate with thiosemicarbazide or inthiosemicarno ζ cyto derivatives.

(Example: Combinations of organic acid lead salts such as caproate, urgonate, lead behenate, and thiourea derivatives such as ethylenethiourea and N-dodenylthiourea.

(M) A combination of higher fatty acid heavy metal salts such as ferric stearate and copper stearate and zinc dialkyldithiocarnooctamate.

(n) Those that form oxazine dyes, such as combinations of resorcinol and nitroso compounds, or those that form azo dyes.

←Those that form azo dyes with diazonium salts and cassonolani (azo-based heat-sensitive layer).

However, in the present invention, 1. The present invention is not limited to the thermochromic composition of this combination, and any thermochromic material that develops color with heat, which is used in the field of thermal copying, can be used.

In the present invention, the heat-sensitive coloring layer is attached to the support.
JI 1-1077m”, preferably 2-5 f/n
L".Supports include high-quality paper, medium-quality paper,
Synthetic paper, plastic film, etc. can be used, but transparent or translucent materials that transmit infrared rays well are preferably used, and the thickness thereof is preferably in the range of 1 to 5 .mu.11.

The heat-sensitive recording material of the present invention is used as a heat-sensitive recording medium in a recording method using a contact reflection printing method.
It is advantageously used as a recording medium when printing from the back using a general thermal head or thermal pen.

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 [Liquid A] Ethyl cellulose 20 parts by weight water
80,.

[Liquid B]

Crystal Violeno Tora Kutsu lO
Heavy sound IS stearic acid amide
15++ Silica 5 Vinyl chloride-vinyl acetate copolymer emulsion (50 parts)
10 II Water
60p The above composition was manufactured in a sale mill.

[Liquid C]

Bisphenol A 20 parts by weight Vinyl chloride-vinyl acetate copolymer emulsion (50 parts) 4
II Water 7
6 [CtL] was prepared by dispersing the above composition in a sail mill.

Next, dry a mixture of base paper (basis weight 30 g/m') and [Liquid C] in a ratio of 1:1.
g/nt" and dry. On top of that, [A
liquid] to a dry weight of 2 Li/m'''' =
Then, thermal paper was obtained.

Example 2 C I) Liquid] Polystyrene emulsion (50%) 40 parts by weight water
60 In Example 1, instead of [Liquid A], [D
Thermal paper was prepared in the same manner except that 1) rt.

Comparative Example Example 1 without O-S-coat is used as a comparative example.

When the paper was brought into close contact with the printed matter from the back and irradiated with an 11 W infrared lamp for 2 seconds, color developed, and when measured with a Macbeth densitometer, the results shown in the table below were obtained.

Table 1 0...Very good △...Good ×...Bad From the results shown in the table, image density is It can be seen that a heat-sensitive recording material with improved clarity can be obtained.

Patent applicant Ricoh Co., Ltd.

Claims (1)

[Claims] (X) Form a thermosensitive coloring layer 11 on the support J・1, on which the thermal conductivity is 0, l 5 kc + 11 / +
++ pullr ・"Higher than C 5) -r ・Thermal sensitivity 11 series characterized by laminating material layers: Record (3 materials).